1. Field of the Invention
The invention relates to a method and a device for coating printed circuit boards as used in electric circuits, integrated circuits and the like.
2. Description of the Related Technology
Printed circuit boards are coated with a fluid coating compound like lacquer, whereupon the coating is dried before the printed circuit boards are processed further. The coating can be applied by having the printed circuit boards on a transport band, and guiding them under a pouring device which produces a pouring curtain falling onto the printed circuit boards. To keep the edges of the printed circuit boards free for grippers and other handling means, covering sheets are used laterally to limit the width of the pouring curtain. Here, it is difficult to avoid extra thickness in the coating at the edges.
The coating can also be applied by spraying the printed circuit boards, wherein problems arise above all in that adjacent machine and conveyor members are also coated with the coating compound and must be cleaned, which is costly. This leads to a correspondingly high consumption of coating compound (overspray). In conventional spray rigs, production has to be interrupted several times a day for cleaning work. This leads to high production costs.